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It's not often that all scientists and government and insurance companies agree, but they do on this point: This year’s peak of the 11-year solar cycle may lead to significant disruption of business communication systems, and bring about a surge in insurance claims. Scientists predict extreme solar weather for the next 12 months, including solar flares and other geomagnetic activity. What would be the effect of a major geomagnetic storm? Stated another way, how well would you or your organization fare in a power failure that lasted years? It's happened before, and it can happen again.

Geomagnetic storms and other extreme solar weather are a realistic threat to vital modern infrastructure, especially electrical power grids, telecommunications networks, and global satellite navigation. In this article, we discuss the nature and history of these events so you can make an educated estimate as to their probability. Hint: They happen more often than you think they do. After a brief overview of what can happen, we offer some modest suggestions as to how you can minimize your exposure, and why (morally and legally) you need to do so now.

What You Should Know About Geomagnetic Storms

A geomagnetic storm is a temporary disturbance of the earth's magnetosphere due to a solar disturbance such as a coronal mass ejection (CME). CMEs release huge quantities of matter and electromagnetic radiation into space, and if the side of the sun experiencing the CME is facing the earth, that's when the problems begin. We are nearing the high point of solar activity this year, and these events will occur with increasing frequency.

The ejected material in a CME consists primarily of electrons and protons. These particles typically take between one and three days to reach Earth. Once the disturbance arrives, it can pose a hazard to satellites and electronic systems both in orbit and on the earth's surface.

How Bad Can It Get?

Geomagnetic storms vary in severity. An index called the Kp scale measures the effects of geomagnetic storms.

Kp Index

NOAA Space Weather Scale (Geomagnetic Storm Level)

KP=5

G1

KP=6

G2

KP=7

G3

KP=8

G4

KP=9

G5

As an example, a G2 is a Moderate geomagnetic storm, which may disrupt HF (High Frequency) communications and even create auroras in areas where they do not normally occur. Even at times of relatively minor events, auroras may sometimes be seen as far south as New York. Storms of longer duration or a higher storm level, however, may cause significant damage.

The strongest on NOAA scale is G5 or Extreme geomagnetic storm. A G5 storm can generate widespread problems, particularly on power grids. Protective systems may trip, and some grid systems may experience complete collapse or blackouts. Massive ground currents resulting from geomagnetic storms flow through electricity distribution networks, sometimes resulting in permanent damage to transformers. Enhanced X-ray and powerful ultraviolet solar radiation during a solar flare also impact radio propagation and telecommunications systems. Solar radiation can even cause a satellite’s orbit to decay, and static electrical discharges often interfere with GPS services for aircraft, particularly those operating at high latitudes (nearest the poles). Spacecraft operations may experience extensive surface charging, problems with orientation, uplink/downlink, and tracking satellites. HF (high frequency) radio propagation may be impossible in many areas for one to two days. Satellite navigation and communication may be degraded. Low-frequency radio navigation may be out of service for hours. And beautiful auroras may be seen as far south as Florida and south Texas.

Examples of Past Solar Events

As recently as a few weeks ago, a moderate solar storm occurred. On March 17, 2013, NOAA/SWPC’s Estimated Planetary K-index showed Kp=6 levels, which are on the threshold of causing problems. This event was “small potatoes” when compared to some of the geomagnetic storms of the past. It is important to consider that two of the most notable events occurred at a time when telegraphs were the dominant mode of communications, not iPhones and computers.

NOTE

According to NOAA/SWPC, a CME that erupted on March 15, 2013, hit Earth’s magnetic field at 06:00 UTC on March 17, 2013.

New York Central Railroad

At 7:04am on May 15, 1921, the entire signal and switching system of the New York Central Railroad below 125th Street was put out of operation due to a solar storm that occurred two days earlier. A fire in the control tower also resulted at 57th Street and Park Avenue. Railroad officials formally assigned blame for a fire that destroyed the Central New England Railroad Station to “the aurora,” because little was known about the nature of these events at the time. One operator reported that he was actually driven away from his telegraph instrument by a flame that enveloped his switchboard and subsequently ignited the entire building.

As part of the same solar event, a telephone station in Sweden was burned out, and the solar storm interfered with telephone, telegraph, and cable traffic over most of Europe. Auroras were visible in the Eastern United States, with reports from as far south as Pasadena, California as the aurora reached its maximum.

Carrington Event

A solar storm in 1859 (known as the Carrington Event) may have been the granddaddy of them all. This powerful geomagnetic solar storm was caused by a CME, which battered the earth's magnetosphere at a time before much in the way of electronic technology even existed. It was observed and recorded by Richard C. Carrington, hence its name. The CME he observed induced what is generally acknowledged as the largest known geomagnetic solar storm on record. The following is a brief account.

From August 28 until September 2, 1859, numerous sunspots and solar flares were observed on the sun. On September 1, 1859, Carrington and Richard Hodgson, another English amateur astronomer, independently made the first observations of a solar flare. Just before noon on that day, Carrington observed the largest in a series of solar flares and resultant CME as it traveled directly toward earth. The trip took only 17.6 hours. (The journey normally takes 3-4 days.) It is believed that the second CME moved so quickly because the first one had cleared the way of ambient solar wind plasma.

Accounts of the geomagnetic storm of 1859 were compiled worldwide. One such account, published by Elias Loomis, describes the observations of Carrington and Balfour Stewart:

On September 1–2, 1859, the largest recorded geomagnetic storm occurred. Aurorae were seen around the world, even over the Caribbean; those over the Rocky Mountains were so bright that their glow awoke gold miners, who began preparing breakfast, because they thought it was morning. People who happened to be awake in the northeastern US could read a newspaper by the aurora's light.

Telegraph systems all over Europe and North America failed, in some cases even shocking telegraph operators. Telegraph pylons threw sparks and telegraph paper spontaneously caught fire. Some telegraph systems continued to send and receive messages - - - completely disconnected from their power supplies!

On September 3, 1859, the Baltimore Americanand CommercialAdvertiser reported:

"Those who happened to be out late on Thursday night had an opportunity of witnessing another magnificent display of the auroral lights. The phenomenon was very similar to the display on Sunday night, though at times the light was, if possible, more brilliant, and the prismatic hues more varied and gorgeous. The light appeared to cover the whole firmament, apparently like a luminous cloud, through which the stars of the larger magnitude indistinctly shone. The light was greater than that of the moon at its full, but had an indescribable softness and delicacy that seemed to envelop everything upon which it rested. Between 12 and 1 o'clock, when the display was at its full brilliancy, the quiet streets of the city resting under this strange light, presented a beautiful as well as singular appearance."